The embodiments described herein relate generally to computer modeling, and more particularly, to systems and methods for generating a computer model of a local component of a turbine engine to account for actual manufacturing tolerances during a computer modeling stage of the component.
In a gas turbine, hot combustion gases flow along an annular hot gas path. Typically, turbine stages are disposed along the hot gas path such that the gases flow through vanes and blades of the turbine stages. The temperature of the hot gas may approach or exceed the permissible material temperature of the turbine blades. To accommodate the hot temperatures, some gas turbines may include a film of cooling fluid, for example cooling air, along the turbine blades. The film of cooling fluid is usually conducted through cooling ducts located within the interior of the blade that is to be cooled, and then conducted via a multiplicity of drilled cooling holes to the outer side of the blade. The cooling holes are machined into the turbine blades at specific locations on the blade and are subject to functional requirements to provide optimal component performance and life span.
In the design stage of the turbine blades, computer aided design models of the cooling holes are sometimes generated. Typical computer aided design allows a user to construct and manipulate complex three dimensional models of objects or assemblies of objects. Moreover, the systems provide a representation of modeled objects using edges or lines, which may be represented in various manners, e.g., non-uniform rational B-splines. These systems may manage parts or assemblies of parts as modeled objects, which typically include specifications of geometry. More particularly, computer aided files contain specifications, from which geometry is generated, which in turn allow for a representation to be generated, such that the systems include graphic tools for representing the modeled objects to the designers.
Manufacturing operations prior to machining the actual cooling holes may introduce significant deviations and/or tolerances into the actual blade as opposed to the nominal design of the blade. Not adequately accounting for the non-nominal deviations in the nominal computer design may result in sub-optimal cooling hole layout which may not meet functional and/or manufacturing specifications resulting in yield loss or scrapped blades. More particularly, geometric variation in hole drilling may result in deviation of the hole true position/orientation from the nominal position/orientation. Some designers simulate the deviations from the nominal design by designing a full computer model of the entire blade. However, a full computer aided model of non-nominal components that is configured to compute functional hole parameters is expensive and time consuming.